SCC2681AC1N28 NXP Semiconductors, SCC2681AC1N28 Datasheet - Page 12

• Manufacturer Part Number: SCC2681AC1N28
• Description: UART 2-CH 5V 28-Pin PDIP Tube
• Manufacturer: NXP Semiconductors

Specifications of SCC2681AC1N28

• Package: 28PDIP
• Number Of Channels Per Chip: 2
• Maximum Data Rate: 0.1152 MBd
• Transmitter And Receiver Fifo Counter: No
• Operating Supply Voltage: 5 V
• Minimum Single Supply Voltage: 4.75 V
• Maximum Processing Temperature: 260 °C
• Maximum Supply Current: 10 mA

The level at the OP pin is the inverse of the bit in the OPR register.
Philips Semiconductors
Table 2. Register Bit Formats
NOTE:
* In block error mode, block error conditions must be cleared by using the error reset command (command 4x) or a receiver reset.
** Please see Receiver Reset note on page 21.
NOTE:
*Add 0.5 to values shown for 0 – 7 if channel is programmed for 5 bits/char.
NOTE:
* See Table 5 for BRG Test frequencies in this data sheet, and “Extended baud rates for SCN2681, SCN68681, SCC2691, SCC2692,
SCC68692 and SCC2698B” in application notes elsewhere in this publication.
NOTE:
*Access to the upper three bits of the command register should be separated by three (3) edges of the X1 clock. A disabled transmitter cannot
be loaded.
NOTE:
* These status bits are appended to the corresponding data character in the receive FIFO. A read of the status provides these bits (7:5) from
NOTE:
2004 Apr 06
OPR bit
the top of the FIFO together with bits (4:0). These bits are cleared by a “reset error status” command. In character mode they are discarded
when the corresponding data character is read from the FIFO. In block error mode, block error conditions must be cleared by using the error
reset command (command 4x) or a receiver reset.
OP pin
Dual asynchronous receiver/transmitter (DUART)
OPR
MR1A
MR1A
MR1B
MR2A
MR2A
MR2B
CSRA
CSRA
CSRB
CSRB
OPCR
CRA
CRB
CRB
SRA
SRB
SRB
0
1
BIT 7
0 = OPR[7]
1 = TxRDYB
RECEIVED
BIT 7
CONTROL
Not used –
must be 0
BREAK*
0 = No
1 = Yes
RxRTS
BIT 7
BIT 7
0 = No
1 = Yes
1
0
OP7
BIT 7
BIT 7
BIT 7
CHANNEL MODE
00 = Normal
01 = Auto-Echo
10 = Local loop
11 = Remote loop
0
1
BIT 6
RECEIVER CLOCK SELECT
0 = OPR[6]
1 = TxRDYA
FRAMING
ERROR*
BIT 6
0 = RxRDY
1 = FFULL
0 = No
1 = Yes
MISCELLANEOUS COMMANDS
BIT 6
BIT 6
SELECT
OP6
BIT 6
1
0
RxINT
BIT 6
BIT 6
See Text
0
1
BIT 5
1 = RxRDY/
See Text
0 = OPR[5]
BIT 5
ERROR*
PARITY
0 = No
1 = Yes
BIT 5
BIT 5
BIT 5
OP5
FFULLB
0 = Char
1 = Block
CONTROL
1
0
ERROR
MODE*
0 = No
1 = Yes
BIT 5
TxRTS
BIT 5
0
1
BIT 4
1 = RxRDY/
0 = OPR[4]
BIT 4
OVERRUN
BIT 4
ERROR
0 = No
1 = Yes
BIT 4
BIT 4
OP4
FFULLA
12
1
0
ENABLE Tx
00 = With Parity
01 = Force Parity
10 = No Parity
11 = Multidrop Mode**
BIT 4
PARITY MODE
0 = No
1 = Yes
BIT 4
DISABLE Tx
CTS
0 = No
1 = Yes
0
1
BIT 3
BIT 3
TxEMT
0 = No
1 = Yes
BIT 3
BIT 3
BIT 3
00 = OPR[3]
01 = C/T OUTPUT
10 = TxCB(1x)
11 = RxCB(1x)
BIT 3
1
0
0 = 0.563
1 = 0.625
2 = 0.688
3 = 0.750
BIT 3
OP3
ENABLE Tx
TRANSMITTER CLOCK SELECT
0
1
0 = No
1 = Yes
BIT 2
BIT 2
BIT 2
TxRDY
0 = No
1 = Yes
BIT 2
0 = Even
BIT 2
PARITY
1 = Odd
TYPE
BIT 2
4 = 0.813
5 = 0.875
6 = 0.938
7 = 1.000
1
0
BIT 2
STOP BIT LENGTH*
See Text
DISABLE Rx
0
1
0 = No
1 = Yes
BIT 1
BIT 1
BIT 1
FFULL
0 = No
1 = Yes
BIT 1
BIT 1
8 = 1.563
9 = 1.625
A = 1.688
B = 1.750
BIT 1
BIT 1
00 = OPR[2]
01 = TxCA(16x)
10 = TxCA(1x)
11 = RxCA(1x)
1
0
CHARACTER
SCC2681
BITS PER
OP2
00 = 5
01 = 6
10 = 7
11 = 8
ENABLE Rx
0
1
BIT 0
Product data
C = 1.813
D = 1.875
E = 1.938
F = 2.000
BIT 0
0 = No
1 = Yes
BIT 0
RxRDY
BIT 0
0 = No
1 = Yes
BIT 0
BIT 0
BIT 0
1
0